Binding configuration missing in recent 4.0.0 builds

The SqueezeBox binding has a config parameter for Callback URL.

In build 3272, if I go to the binding config in Main UI, the Callback URL parameter is visible.

However, in build 3299, all I see is the option to set the log level.

In both builds, I can see the config info coming back to the browser in response to this rest call